Monocrystalline silicon →
The decade mono-Si went from premium wafer to 97.7% of world module production: PERC replaced Al-BSF, then TOPCon overtook PERC in a two-year crossover that ITRPV's roadmap called in advance; commercial efficiency rose from about 17% to a 22.7% weighted average with a 24.8% top value, and prices fell from US$0.716 to US$0.258 per watt in constant terms (ITRPV, Fraunhofer ISE, NREL, IEA PVPS). The record that anchors every module horizon on the roadmap.
BatteriesThe lithium-ion decade →
From the Powerwall announcement of April 2015 to the LFP takeover: the chemistry that launched the category lost to the one optimised for stationary duty, safety standards were written in response to incidents rather than ahead of them, and pack prices fell 93% to reach US$70/kWh for stationary storage: below EV packs for the first time (BNEF, IRENA, IEA, regulator recall records). The record behind every battery horizon and safety criterion on this site.
InvertersFrom converter to controller →
The device that converted DC and stepped out of the way became the operating system of a distributed energy asset: silicon IGBT's 96–97% ceiling gave way to 99% silicon carbide, DC-coupled hybrids won the battery integration moment, and a fragmented 2015 market consolidated until two firms held 55% of 589 GWac (IHS, Wood Mackenzie, S&P Global, NREL). The record behind the roadmap's conversion-technology horizons.
The demand contextThe electrification shift →
The system-level decade the three product records deployed into: EVs from under 1% to 25% of new car sales, grid storage from a 1 GWh cumulative base to 112 GW added in a single year, solar past 2.25 TW and 10% of world electricity (IEA, BloombergNEF, IEA-PVPS, Ember). The demand backdrop every product projection quietly assumes: stated here so the assumption is visible and sourced.
Read the electrification record →
How this record is used
Each segment is historical only: observed transitions, observed ranges, sources named inline, disagreements between sources preserved rather than averaged. The roadmap carries the projections; this record supplies the transition speeds, cost-curve calibrations and roadmap-versus-actual hit rates those projections are read against. Segments are reviewed with each roadmap update. Last review: July 2026.